Termination of a Material Definitive Agreement Termination of Credit and Guaranty Agreement On May 13, 2026, in connection with the consummation of the Mergers (as defined below), Sun Country, Inc., a Minnesota corporation and a wholly owned subsidiary of Sun Country Airlines Holdings, Inc., a Delaware corporation (“ Sun Country ”) terminated the Credit and Guaranty Agreement, dated as of March 24, 2025, by and among Sun Country, Inc., Sun Country, as Guarantor, MUFG Bank, Ltd., as a Lender,…

Sun Country notified the Nasdaq Stock Market LLC (“ Nasdaq ”) of the Closing and requested that Nasdaq suspend trading of Sun Country Common Stock. As a result, trading of Sun Country Common Stock on Nasdaq was suspended prior to the opening of trading on the Closing Date. On the Closing Date, Sun Country also requested that Nasdaq file with the U.S. Securities and Exchange Commission (the “ SEC ”) a notification of removal from listing and registration on Form 25 to effect the delisting of S…

As a result of the Mergers, a change of control of Sun Country occurred and Sun Country became a wholly owned subsidiary of Allegiant. Allegiant obtained the funds necessary to fund the Mergers through a combination of cash on hand and debt financing.

Completion of Acquisition or Disposition of Assets. Merger Agreement Closing On May 13, 2026 (the “ Closing Date ”), Allegiant Travel Company, a Nevada corporation (“ Allegiant ”), completed the previously announced acquisition of Sun Country pursuant to the Agreement and Plan of Merger (the “ Merger Agreement ”), dated January 11, 2026, by and among Allegiant, Sun Country, Mirage Merger Sub, Inc., a Delaware corporation and a direct wholly owned subsidiary of Allegiant (“ Merger Sub 1 ”), an…

Director — Marion Blakey, Jude Bricker, Thomas C. Kennedy, Patrick O’Keeffe, Gail Peterson, Kerry Philipovitch, Wendy Schoppert, Jennifer Vogel: Departures were due to the consummation of Mergers and not disagreements with Sun Country.

As a result of the First Merger, each Share that was issued and outstanding immediately prior to the First Effective Time was converted into the right to receive the Merger Consideration. Accordingly, at the First Effective Time, holders of Sun Country Common Stock immediately before the First Effective Time ceased to have any rights as stockholders in Sun Country, other than their right to receive the Merger Consideration pursuant to the Merger Agreement.

Other Events. As previously announced, on January 11, 2026, Sun Country Airlines Holdings, Inc., a Delaware corporation (“ Sun Country ”), entered into an Agreement and Plan of Merger (the “ Merger Agreement ”) with Allegiant Travel Company, a Nevada corporation (“ Allegiant ”), Mirage Merger Sub, Inc., a Delaware corporation and a direct wholly owned subsidiary of Allegiant (“ Merger Sub 1 ”), and Sawdust Merger Sub, LLC, a Nevada limited liability company and a direct wholly owned subsidiar…

Results of Operations and Financial Condition. On February 5, 2026, Sun Country Airlines Holdings, Inc. issued a press release announcing its financial results for the year and fiscal quarter ended December 31, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated by reference herein. The information contained in this Item 2.02, including Exhibit 99.1 attached hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934,…

Entry into a Material Definitive Agreement. Merger Agreement On January 11, 2026, Sun Country Airlines Holdings, Inc., a Delaware corporation (the “ Sun Country ”), entered into an Agreement and Plan of Merger (the “ Merger Agreement ”) with Allegiant Travel Company, a Nevada corporation (“ Allegiant ”), Mirage Merger Sub, Inc., a Delaware corporation and a direct wholly owned subsidiary of Allegiant (“ Merger Sub 1 ”), and Sawdust Merger Sub, LLC, a Nevada limited liability company and a dir…

Chief Commercial Officer — Colton Snow: The filing discloses the internal promotion of Colton Snow to Chief Commercial Officer and Stephen Coley to Chief Operating Officer, representing a succession of existing senior staff rather than a departure.

Chief Accounting Officer — Christopher Mangione: The filing discloses the appointment of an internal employee as Chief Accounting Officer, replacing an interim arrangement, which is a standard succession event rather than a loss of a senior executive.

Chief Accounting Officer — John Gyurci: The Chief Accounting Officer is resigning, which is a genuine departure of a senior officer, though mitigated by the CFO assuming the role interimly and the lack of any stated disagreement.

Results of Operations and Financial Condition. On October 29, 2025, Sun Country Airlines Holdings, Inc. issued a press release announcing its financial results for the fiscal quarter ended September 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated by reference herein. The information contained in this Item 2.02, including Exhibit 99.1 attached hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amen…

Chief Revenue Officer — Grant Whitney: The Senior Vice President & Chief Revenue Officer is separating from the company with separation benefits, representing a genuine executive departure without a named successor.

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth in

Termination of a Material Definitive Agreement. On September 26, 2025, the Company applied the proceeds of the Term Loan Facility to repay in full the indebtedness outstanding under the Existing Term Loan Facility. The information set forth above under

Entry into a Material Definitive Agreement. Term Loan Credit Facility On September 26, 2025, Sun Country Inc. (d/b/a Sun Country Airlines) (“Sun Country”), a wholly owned company of Sun Country Airlines Holdings, Inc. (the “Company,” “we,” “us” or “our”) entered into a $108,000,000 Term Loan Facility Agreement among Sun Country, the lenders party thereto and UMB Bank, National Association, as administrative agent and mortgagee (the “Term Loan Facility”). The Term Loan Facility will be drawn i…

Director — Wendy Schoppert: The filing announces the appointment of a new independent director to the Board, which is a routine governance event and not a departure of a senior executive.

CFO — D. Torque Zubeck: The filing announces the appointment of a permanent external CFO to replace an interim officer, which is a standard succession event rather than a sudden loss of a sitting executive.

Results of Operations and Financial Condition. On July 31, 2025, Sun Country Airlines Holdings, Inc. issued a press release announcing its financial results for the fiscal quarter ended June 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated by reference herein. The information contained in this Item 2.02, including Exhibit 99.1 attached hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the…

Results of Operations and Financial Condition. On May 1, 2025, Sun Country Airlines Holdings, Inc. issued a press release announcing its financial results for the fiscal quarter ended March 31, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated by reference herein. The information contained in this Item 2.02, including Exhibit 99.1 attached hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the…

CFO — Dave Davis: The CFO and President resigned effective immediately, but the company appointed an internal interim successor and stated there was no disagreement, indicating an orderly transition rather than a sudden loss shock.

Entry into a Material Definitive Agreement. On March 24, 2025, Sun Country, Inc. (the “Borrower”), a wholly-owned subsidiary of Sun Country Airlines Holdings, Inc. (the “Company”), entered into a four year $75,000,000 Revolving Credit Facility (the “Revolver”) with UMB Bank, National Association, as administrative agent, MUFG Bank, Ltd. and Sumitomo Mitsui Banking Corporation, as lenders, and any other lenders named therein. The commitments under the Revolver represent a $50,000,00 (200%) inc…

SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. Date: March 28, 2025 Sun Country Airlines Holdings, Inc. By: /s/ Erin Rose Neale Name: Erin Rose Neale Title: Senior Vice President, General Counsel and Secretary

Entry into a Material Definitive Agreement. On March 17, 2025, Sun Country, Inc., a wholly-owned subsidiary of Sun Country Airlines Holdings, Inc., entered into that certain Credit Card Program Agreement with Synchrony Bank (the “Agreement”). The Agreement provides for a new co-brand credit card program between the parties. Subject to certain exceptions, the Agreement has a term of seven years following the launch of the co-brand credit card program with automatic successive one year renewal…